前往火星的飞行至少需要两年时间

　　A mission to Mars would take at least two years

　　布里登斯廷说，一次往返火星的行程至少需要两年时间。

　　A round-trip voyage to the Red Planet would last at least two years, Bridenstine said.

　　根据它们的轨道，火星距离地球至少有3300万英里。相比之下，月球距离我们的星球只有23.9万英里，也就是几天的行程。

　　Depending on their orbits, Mars is at least 33 million miles from Earth. By contrast, the moon is only about 239,000 miles -- several days' journey -- from our planet.

　　NASA发言人谢丽尔•华纳(CherylWarner)表示，地球和火星每26个月会处在太阳的同一侧，这是最好的分离期。到火星旅行需要6到9个月，这取决于工作人员何时离开。

　　Earth and Mars are on the same side of the Sun about every 26 months, and these are the best windows to depart, NASA spokeswoman Cheryl Warner said. Traveling to Mars would take six to nine months, depending on when the crew leaves.

　　最快到达火星的方法是通过霍曼转移轨道(Hohmann Transfer orbit)，这需要最少的能量，被认为是最有效的。

　　The quickest way to get to Mars is via the Hohmann Transfer orbit, which requires the least energy and is considered the most efficient.